July – Sept

Castle Rock Co Weather Climate Summary July – September 2017

A statistical look and discussion of weather recorded for Castle Rock Colorado. This information was collected and recorded via my weather station in the Meadows in the town of Castle Rock. It is in no way an “official” record, just simply what was recorded by my station. These stats include snowfall, temperatures, precipitation, wind intensity and direction for the month.

July 2017

General Summary

July 2017 saw the return of monsoon season in full force for some areas of Colorado while others were left high and dry!

Most of the Palmer Divide Region received a ton of rain, mainly in the second half of the month. Here’s the observed 30 day total through July 2017 from the National Weather Service:

Douglas, Elbert, Jefferson and El Paso counties with other areas along the Palmer Divide saw anywhere from 2-5 inches.

If you take a full snapshot of the state, the South and Southeastern bias on monsoon moisture really shows!

South central and Southeastern parts of the state received the bulk of the moisture for July 2017.

Denver International Airport only recorded 0.6 inches of precipitation for the month, meaning it is very, very dry for areas in and around Denver! Colorado Springs on the other hand got over 6 inches of total precipitation!

Castle Rock Weather Summary

I’m trying some new graphics and displays with some new and fun ways to display my weather data this month, let me know what you think!

Departure From Normal Temperature and Precipitation in July 2017

Analysis

The month overall was very close to average on mean temperature… this means that the day time and night time temperatures averaged together for the month were very close to where we expected them to be with the month finishing only 0.48 degrees above average.

For precipitation, the monsoon provided ample amounts of moisture to the area. Most areas in and around Castle Rock ranged from between 2-5 inches. Some localized areas saw 5+ inches of precipitation for the month. As you can see from the graphic above, most of this came late in the second half of the month.

July 2017 Highlights

August 2017

General Summary

August 2017 was a mixed bag for Colorado in terms of continuing the monsoon pattern. Some areas continued to see rain and thunderstorms while others were left a bit high and dry. In Castle Rock for example, whether you saw above or below average rainfall depended on what side of I-25 you lived on!

Here’s the departure from average precipitation through August 2017 from the National Weather Service:

Isolated areas saw above average precipitation while others saw below average. This departure from normal precipitation graphic shows how much above or below average precipitation was for August 2017

Castle Rock Weather Summary

Keep in mind, my weather station is on the West side of I-25 so depending on where you live around town, you may have seen much more rain than I did. Alternatively, temperatures were pretty consistent for all areas across the Palmer Divide, with nearly everyone ending below average for the month.

Departure From Normal Temperature and Precipitation in August 2017

Analysis

For the Castle Rock area, the monthly mean temperature finished 2.35 degrees below the 30 year mean temperature. This is pretty notable because August is typically on of our warmest months of the year.

Precipitation was a bit mixed, some areas were a bit dry and some areas were a bit wetter. Areas along the Northern and Eastern parts of the state were wetter than normal along with Southeastern Colorado, which saw several large, heavy, slow-moving thunderstorms. In terms of closer to home, areas East of I-25 in and around Castle Rock ended up between .5-1 inches above normal, while areas along the West side of town (like the meadows) were 1-2 inches below average.

August 2017 Highlights

You’ll note that Castle Rock did not hit 90 degrees this August. That is a bit unusual, but not surprising… the daytime temperatures were lower so the nighttime temperatures followed. This meant an overall lower mean temperature and what put the month well below average for temperatures.

September 2017 Sneak Peak

Climate Prediction Center shows equal chances for above and below average precip along the front range. The mountains however will have a better chance for above average precipitation.

Latest CPC outlook for September shows a better than average chance for above average temps across the Western United States. I’d expect lots of ridging to the West and warm temperatures… how Colorado fares with this pattern will depend on where the ridge sets up, and how strong it is.

Given the current pattern I’d expect September to start off drier and warmer than normal. I fully expect the month to finish warmer than average given recent trends but would not be surprised to see the month finish close to average (only slightly above) For precipitation, I expect September to finish near normal, but keep in mind that September is a historically dry month!